Obstetric implications of the factor V leiden mutation: a review.

Factor V Leiden (FVL) is a newly discovered genetic mutation that impairs one of the body's naturally occurring anticoagulation systems. The result is resistance to activated protein C and a predisposition to thrombosis. FVL is the most common cause of primary and recurrent venous thromboembolism in the pregnant and nonpregnant state. The FVL gene is common in the general population and transmitted in an autosomal dominant fashion. When FVL is combined with the prothrombotic state of pregnancy, the result is an increased propensity to manifest a number of pregnancy complications. These include recurrent pregnancy loss and stillbirth, severe and early-onset preeclampsia, placental abruption and possibly, intrauterine growth restriction. It remains unknown whether thromboprophylaxis is effective in ameliorating these pregnancy complications. The current literature and management recommendations are highlighted in this article.